Fuel pump



R. E. KALERT, .J 3,179,055

FUEL PUMP FiledAug. 51. 1962 April 2o, 196s ai@ 'I Y l 3 )I L F'IG.6. 5/

INVENTOR RALPH E. KALERT JR.

AGENT United States Patent O 3,179,055 FUEL PUMP Ralph E. Kalert, Jr., Granite City, Ill., assigner to ACF Industries Incorporated, New York, N.Y., a corporation of New Jersey Filed Aug. 31, 1962, Ser. No. 220,638 7 Claims. (Cl. 10S- 44) The invention is directed to an auxiliary pumping unit which may be used in fuel systems, particularly for pumping fuel to a carburetor or other air and fuel mixing device.

Many small carburetors, utilized with small two cycle or four cycle internal combustion engines, have a fuel system in which fuel is fed by gravity from an elevated tank into the carburetor -or mixing valve of the engine. The fuel and air mixing devices used with such engines may consist of various types of mixing valves or carburetors, in which the air is sucked into a tubular conduit and fuel is metered into the conduit to mix with the air flow passing to the engine. The metering of the fuel normally is done by restricted passageways leading through the carburetor to the mixing conduit and is dependent upon the suction or vacuum provided by the engine during operation. The pressure of the fuel flowing through the carburetor is also determined by the level of fuel in the tank above the inlet valve. As the level of fuel in the elevated tank drops, the pressure on the fuel owing through the carburetor drops and thus less fuel ilows into the mixing conduit. If the restrictions in the carburetor fuel passages are adjusted for a full fuel tank with maximum fuel pressure, then as the fuel level drops, the air and fuel mixture tends to lean out and causes the engine to lose power. On the other hand, if the restrictions in the fuel passages are adjusted for another level, such as a low level of fuel in the fuel tank, a greater level of fuel will cause an enrichment of the fuel flowing to the engine. Such engines are often used with lawnmowers or other devices in which the machine is tilted at an angle during operation. The fuel level in the tank obviously is changed to either enrich or lean out the fuel and air mixture fed to the engine. It is thus therefore an advantage to provide a fuel source for such engines so that the pressure of fuel entering the air-fuel mixture device can be substantially constant. Gravity fed fuel tanks have been widely used because of the economy in construction and operation. A fuel pump in the system between the tank and carburetor will normally provide fuel at a constant pressure so that fixed adjustments can be used for ali conditions of engine operation. However, a fuel pump normally is not an inexpensive item and thus is not usually used with low cost engine installations.

It is therefore an object of this invention to provide an inexpensive economical fuel pump, which can be adapted for use with a carburetor or at any part in a fuel system to provide a constant ow of fuel to any desired point.

It is another object of this invention to provide an economical fuel pump which can be adaptable to various types of installation. It is another object of the invention to provide an inexpensive fuel pump for use with a carburetor or an air-fue] mixture device which has universal adjustments for adaptation to various installations.

The invention is in a small inexpensive pump, which is easily adaptable for attachment at any point in a fuel system. Such a pump can be connected to a carburetor or to the engine or at any point in the line between the source of fuel and the engine. The novel pump includes a plastic body consisting of a pair of tted members which can be snapped together with a pumping diaphragm in between. One body includes the valving means neces- ICC sary for providing an operative fuel pump. The other body includes a pressure chamber for actuating the pump diaphragm. The two bodies can be swiveled one relative to the other to provide universal adjustment and mounting. The pump itself can be attached to a fitting fixed to the carburetor or another part of the fuel system. A carburetor can receive the pump with a universal attachment so that the pump can be positioned at any desired angle to comply with mounting installation.

FIGURE l is an elevational view of the novel fuel pump in accordance with the invention.

FIGURE 2 is a sectional view in elevation of the pump of FIGURE l showing a mounting of the pump on a fitting.

FIGURES 3 and 4 are sectional views of the pump of FIGURES 1 and 2 and on section lines 3 and 4 of FIG- URE 2.

FIGURE 5 is a plan view showing a mounting of the novel pump structure on a carburetor.

FIGURE 6 is a partial sectional view showing details of mounting the novel pump on a carburetor.

The main body structures of the novel fuel pump 10 consist of plastic members 12 and 14 tted together. As disclosed in FIGURE 2, member 12 is substantially an inverted cylindrical cup structure having an annular groove 16 formed around the inner surface of the rim of the cup. The lower member body 14 is a substantially cylindrical body structure having an annular lip formation 18 protruding outwardly from the perimeter of the upper opening of the body member 14, as shown in FIGURE 2. The two body members are designed so that the upper cylindrical end of body 14 will coaxially telescope into the open rim of the cup member 12 and the lip 18 will snap into the annular groove 16 of the body member 12. The lip 13 and groove 16 are designed such that the rim of member 12 must expand by a flowing of the plastic material to permit the lip 18 of member 14 to enter and snap into the groove 16. The lip 18 is formed slightly larger than groove 16 so that there will be a tight tit between the two because of this mismatch.

A flexible thin circular pump diaphragm 22 is lfitted on an annular shoulder 24 formed within the cup member 12. When the lip 18 is snapped into the annular groove 16, the end of the cylindrical member 14 is forced tightly onto the shoulder 24 to hold `and form a fuel-tight seal between the diaphragm and Vthe portions of members 12 and 14 with which the diaphragm 22 is in con-tact. The diaphragm 22 forms a `substantially closed air chamber 28 with the housing body member 12. A nipple 26 is formed integrally with the plastic body 12 and extends laterally substantially normal to the common axis of body members 12 Iand 14. Nipple 26 is formed with a longitudinal passage 23 for admitting pulsating air into the interior of `the chamber 28. A nipple fitting 35, `adapted t-o receive a flexible rubber tubing is molded with the body member 14 and extends ou-twardly substantially normal to the axis of body 14. Fitting 35 is formed with an inlet conduit 36 leading into the body member 14.

The body member 14 consists of a cylindrical plastic casting having an upper recess 31 forming with the diaphragm 22 a fuel pumping chamber 32. A passage 38 extends downwardly from recess 32 and makes connection with the inlet conduit 36 extending laterally inwardly into the body member 14 to form therewith a fuel inlet passage to the chamber 32. A second cylindrical recess 42 is formed in the lower portion of the body member 14 and is formed in a short boss structure 41 extending from the lower surface of the body member 14. An arcuate space 40 connects the fuel pumping chamber 32 with the cylindrical recess 42 to form an outlet passage from 3 ichamber 32. As shown in detail in FIGURES 2 and 4, 'the arcuate recess is formed through rthe portion of bod`y I4 separating the chamber 32 from the recess 42. A small ledge 43 in the body member I4 extends into the larcuate recess 4t) to form a valve 'stop as described below.

A 4check valve subassembly is mounted within the fuel pumping chamber and consists of a thin flexible valve disk 44 formed of a fuel resistant rubber or flexible plastic such as mylar. A pair of annular valve flaps 45 and 46 are formed integrally in the disk 44, as shown in FIG- URE 4. rThe inlet valve flap 45 extends over the inlet passage 38. The adjacent portion of body member 14 forming the opening into inlet 38 constitutes an inlet valve seat and support for the inlet valve ap 45, as shown in FIGURE 2. In a similar manner the outlet valve flap 46 extends over the arcuate outlet passage 40 and is spaced above the ledge 43, and as indicated in FIGURE 2. A valve plate structure 48 is mounted over valve disk 44 and is fixed to the upper surface of the body member 14 within the cylindrical recess 3l by means of mounting screws 4?, as shown specifically in FIGURE 3. The mounting screws 49, as well as the plate 48, hold the disk 44 in place. An aperture 50 through plate 43 forms an outlet opening .through the plate aligned with the outlet passage 4t) through the body member 14. The immediate periphery of aperture 50 provides an outlet valve seat Ifor the valve flap 46 and the projecting ledge 43 within the annular passage 4t? provides .a stop for ythe downward displacement of -ap 46, as seen in FIGURE 2. Plate 48 has an upset portion 52 extending over and spaced above the inlet valve ap 45 to provide a stop for the movement upwardly of the valve ap, as viewed in FIG- URE 2.

The cylindrical recessy 42 is adapted to receive either a -litting 54 of the type shown in FIGURE 2 or to receive a portion 56 of a carburetor, as shown in FIGURE 6, in which lthe fuel pump is shown mounted on a carburetor 60. In FIGURE 2, the fitting may be either by a nipple structure inserted into the recesses 42 with a tight press-fit, or the fitting may have an annular groove 57 to receive therein an annular rib construction 58 formed on the inner surface of the cylindrical recess 42. The groove and rib construction 57 and 58 permit a fuel-tight connection 'between the fitting 54 and the pump 10. Furthermore, it permits a rotatable orientation of the pump relative to the fitting 54. Fitting 54 itself may be fixed in any manner such as a threaded construction 62 to a carburetor or into any portion of a fuel line between a fuel source and the carburetor. A gasket 55 may be fitted between the fitting 54 and the outer rim of the small boss 4I of the pump body portion 14.

A fuel system is shown in FIGURE 5, in which the pump 10 is mounted on the carburetor 60. The inlet nipple is connected by a fuel line schematically shown at 63 to a source of fuel, such as a fuel tank 64. The pulsating air passage 23, in nipple 26, extending into the upper air chamber 28 -is connected by a flexible line 65 to the crankcase C of an engine E.

The conventional parts of the carburetor are shown as an air filter housing 66 joined to a tubular air and fuel mixture conduit 67. A throttle 63 and a choke valve 69 are indicated as rotatably mounted in the conduit 67. The downstream end of carburetor 60 is fitted with a flange 74 for mounting lthe carburetor to the manifold M of the engine E as by studs 76, for example. The engine E, with which the pump I0 is normally to be used, may consist of a two cycle engine in which the air in the crankcase undergoes both a compression and expansion by operation of the engine piston. During the compression of `the air in the crankcase, air will be forced throughthe passage 65 into the pump chamber 28 to force the diaphragm 22 downwardly, as viewed in FIGURE 2. Upon the expansion of the air within the engine crankcase, due to movement of the piston, air pressure in pump chamber 28 drops below the pressure within the fuel pump chamber 52, which forces the diaphragm upwardly. During engine operation, the diaphragm 44 is caused to reciprocate upwardly and downwardly to provide a pumping action. With the pumping chamber 32 connected through conduit 63 to a source of fuel, atmospheric pressure on the surface of the fuel in Itank 64 will force fuel through the fuel line 63 into the pumping fuel chamber 32 as the diaphragm is sucked upwardly by depression in the engine crankcase. However, upon theV compression of air in the crankcase, air pressure greater than atmospheric will be exerted on the upper surface of diaphragm 22 to force the fuel fr-om chamber 32 through the outlet passage 40 and into the tting 54.

During the upward movement of pump diaphragm 22, the inlet valve flap is raised against the stop member 52 `to permit fuel to flow easily into chamber 32. However, on the downward movement of pump diaphragm 22, the inlet valve flap 45 presses against the inlet valve seat or -rim of the lfuel passage 3S to prevent fuel from flowing back into the inlet line 63. Upon the upward movement in a pumping stroke of the diaphragm 22, the outlet valve flap 46 is prevented from movement by reason of its being sucked against the outlet valve seat or rim of the opening in plate 4S. This prevents any suction from the outlet of the pump .back into the pumping chamber. Upon the discharge pumping stroke, however, the outlet flap 46 is permitted to be moved by the fuel downwardly away from the Ioutlet valve seat, and allow fuel to how through the outlet passage 40.

The showing of the installation of the pump 10 on carburetor 60, in FIGURE 6, is by way of example only. In this installati-on, a fitting of the type 54 ofrFIGURE 2 is not used and instead a boss 56 is used which will receive the `cylindrical recess 42 of the pump with a press-fit. The parts of the pump shown in FIGURE 6 are identical to those described above for FIGURES 2, 3 and 4, and accordingly they are not all indicated numerically. The operation of ythe pump 10 in FIGURE 6 is the same as described above and fuel pumped through the pump by the diaphragm 44 passes downwardly through the cylindrical recess 42 and through the boss 56 into an inlet passage 71 of the carburetor. Fuel flow through this passage is controlled by a needle valve 73 which is operated from one end 70 of a lever 72 pivotally mounted from a portion of the carburetor body 6l. The other end of the lever is not shown, but may be operatively connected to a oat responsive to fuel level in fuel chamber 75 or to a diaphragm responsive to the flow of fuel from chamber 75. Carburetor may be of any well-known type, or of a design described in my copending application Serial Number 213,358, filed July 30, 1962. When the amount of fuel in chamber 75 is reduced by engine operation lever 72 becomes operative and is rotated counterclockwise as viewed in FIGURE 6, to allow valve 71 to be opened by gravity and fuel pressure from pump lil. Upon filling chamber 75 toa predetermined value, lever 72 is rotated clockwise to move valve 71 upwardly to stop fuel flow from pump 10.

Pump It) fixed to a fitting 54 can be connected anywhere in the fuel line between the carburetor and the fuel tank 63. In some installations, it is advantageous to mount the pump as conveniently close to the engine E so that the air pulse line need not be overly extended. For example, in some outboard installations, the pump It) can be mounted directly on the engine crankcase by an appropriate fitting, thus eliminating line 65 completely.

The particular pump structure shown and described above is one which can be molded very easily from plastic materials, such as an .acetal resin. Only the body structure `14, if necessary, requires a minimum amount of machining to provide the required threaded apertures for the valve mounting screws 49. The parts then are merely snapped together and may be press-fitted or snapped onto a carburetor attachment boss or a separate fitting, as shown. The body members 12 and I4 are coaxally .5 mounted with matching cylindrical portions fitted together. This enables one member to be rotated one relative to the other about the common axis to provide any desired angular separation between the inlet nipple 36 and the air nipple 26. This permits a type of universal adjustment allowing adaptation of the pump to any carburetor or any engine installation without requiring a specific fixed arrangement of the nipples for each particular installation. Furthermore, the valve body member 14 of the pump is also coaxially mounted with the fitting 56 of the carburetor or the separate fitting S4, so as to provide a universal angular adjustment of the inlet nipple 36 relative to the carburetor or fitting. These provisions of these angular adjustments for pump installation enables the use of this pump design in various positions and requiring different relative arrangements and positioning of the inlet nipples and the outlet boss.

I claim:

1. A pulse pump for a fuel system, said pump comprising a cup-shaped body member, a cylindrical body member having a surface recessed within one end thereof, means coaxially mounting said body members together with the rim of said cup-shaped member telescopically joined to said one end of said cylindrical body member, a circular diaphragm positioned across and sealed at its periphery between said rim of said cup-shaped member and said one end of said cylindrical body member to form an air chamber with the cup-shaped member and a fuel chamber with said recessed surface, said cylindrical body member having an inle-t passage and an outlet passage extending from said fuel chamber, and check valves within said inlet and outlet passages, said cup-shaped member having a first nipple for connection to a source of air pulsations extending outwardly therefrom and away from the common axis of said members, said first nipple having a passage therethrough opening into said air chamber, said cylindrical member having a second nipple extending outwardly therefrom and away from said common axis, said second nipple including a portion of said fuel inlet passage, said mounting means comprising an intertitting lip and groove arrangement on said cup-shaped body member and said cylindrical body member to permit said body members to be snapped together, said lipand groove arrangement being the sole rneans holding said body members together and said diaphragm in sealed relation between the body members and providing angular displacement of one of said members relative to said other member whereby one of said nipples may be indexed relative to the other, said cylindrical body member having a cylindrical recess within the other end thereof to mount said pump on a support for rotation relative to the support about an axis parallel to the common axis of the body members, the axis of said cylindrical recess being substantially normal to said nipples to provide angular displacement of said nipples relative to said support.

2. A pulse pump for a fuel system, said pump comprising a cup-shaped body member, a cylindrical body member having a surface recessed within one end thereof, means coaxially mounting said body members together with the rim of said cup-shaped member telescopically joined to said one end of said cylindrical body member, a circular diaphragm positioned across and sealed at its periphery between said rim of said cupshaped member and said one end of said cylindrical body member to form an air chamber with the cup-shaped member and a fuel chamber with said recessed surface, said cylindrical body member having an inlet passage and an outlet passage extending from said fuel chamber, a-valve diaphragm fixed to said recessed surface and hav ing a first cutout valve flap closing said inlet passage and a second cutout valve flap extending over said outlet passage to close said outlet passage, said cup-shaped member having a iirst nipple for connection to a source of air pulsations extending outwardly therefrom and away from the common axis of said members, said first nipple having a passage therethrough opening into said air chamber, said cylindrical member having a second nipple extending outwardly therefrom and away from said common axis, said second nipple including a portion of said fuel inlet passage, said mounting means providing angular displacement of one of said members relative to said other member whereby one of said nipples may be indexed relative to the other, said cylindrical body member having a cylindrical recess within the other .end thereof for movably mounting said pump on a support, the axis of said cylindrical recess being substantially normal to said nipples to provide angular displacement of said nipples relative to said support.

3. A pulse pump for a fuel system, said pump comprising a pair of intertting molded plasticbody members, one of the body members being cup-shaped and having an outer annular rim and an annular shoulder adjacent the rim forming a seat, the other of said body members having an annular extension telescoping within the cup-shaped member and adapted to be disposed adjacent said annular shoulder, an annular lip on the outer surface of said annular extension and a complementary annular groove on the inner surface of said annular rim receiving said lip and holding the body members together when the annular extension is pressed within said rim, and a circular diaphragm positioned across and sealed at its periphery between the annular extension and said annular shoulder to form an air chamber with one body member and a fuel chamber with the other body member, the body member forming the air chamber having an integral first nipple for connection to a source of air pulsations extending outwardly therefrom generally at a right angle to the common axis of the body members, the body member forming the fuel chamber having an inlet passage and an outlet passage communicating with said fuel chamber and an integral second nipple extending outwardly therefrom generally at a right angle to said common axis, said second nipple including a portion of said fuel inlet passage for connection to a fuel source, said body members being rotatable relative to each other about said common axis while the body members are held together by said annular lip and groove whereby either of said nipples may be indexed relative to the other.

4. A pulse pump as set forth in claim 3 wherein said cup-shaped body member forms the air chamber and the other body member forms the fuel chamber.

5. A pulse pump for a fuel system, said pump comprising a pair of interfltting molded plastic body members, one of the body members being cup-shaped and having an outer annular rim and an annular shoulder adjacent the rim forming a seat, the other of said body members having an annular extension telescoping within the cup-shaped member and adapted to be disposed adjacent said annular shoulder, an annular lip on the outer surface of said annular extension and a complementary annular groove on the inner surface of said annular rim receiving said lip and holding the body members together when the annular extension is pressed within said rim, and a circular diaphragm positioned across and sealed at its periphery between the annular extension and said annular shoulder to form an air chamber with one body member and a fuel chamber with the other body member, the body member forming the air chamber having an integral first nipple for connection to a source of air pulsations and projecting outwardly therefrom in a direction generally at a right angle to the common axis of the body members, the body member forming the fuel chamber having an integral second nipple projecting outwardly therefrom in a direction generally at a right angle to the common axis of the body membrs to form at least a portion of a fuel inlet passage for connection to a fuel source, said body member with the fuel chamber having an outlet passage communicating with the fuel chamber and extending therefrom in a direction generally parallel to the common axis of the body members and adapted for connection to a support for the pump which permits rotation of the pump relative to the support about an axis parallel to the common axis of the body members, the lip and groove providing rotation of either of the body members relative to the other body member about the common axis of the body members whereby either of the nipples may be indexed relative to the other, flapper check valve means in said fuel chamber comprising a disk of exible material having a pair of cuts therein to form a apper check valve in said inlet passage and a apper check valve in said outlet passage, and a retainer plate holding the disk in the fuel chamber and having an outlet aperture therein adapted to be closed by the outlet check valve, said body member forming thefuel chamber having a recess into which said outlet check valve may flex to open said outlet aperture.

6. A pulse pump for a fuel system, said pump comprising a pair of intertting molded plastic body members, one of the body members being cup-shaped and having an outer annular rim and an annular shoulder adjacent the rim forming a seat, the other of said body members having an annular extension telescoping within the cupshaped member and adapted tobe disposed adjacent said annular shoulder, an annular lip on the outer surface of said annular extension and a complementary annular groove on the inner surface of said annular rim receiving said lip and holding the body members together when the annular extension is pressed within said rim, and a circular diaphragm positioned across and sealed at its periphery between the annular extension and said annular shoulder to form an air chamber with one body member and a fuel chamber with the other body member, the body member forming the air chamber having anintegral first nipple for connection to a source of air pulsations and projecting outwardly therefrom in a direction generally at a right 35 angle to the common axis of the body members, the body member forming the fuel chamber having anv integral second nipple projecting outwardly therefrom in a direction generally at a right angle to'the common axis of the body members to form at least a portion of a fuel inlet passage for connection to a fuel source, said body member with the fuel chamber having an outlet passage communicating with the fuel chamber and extending therefrom in a direction generally parallel to the common axis of the body members and adapted for connection to a support for the pump which permits rotation of the pump relative to the support about an axis parallel to the common axis of the body members, the lip and groove providing rotation of either of the body members relative to the other body member about the common axis of the body members whereby either of the nipples may be indexed relative to the other, and a check valve in each of said inlet and outlet passages.

7. A pulse pump as set forth in claim 6 wherein said cup-shaped body member forms the air chamber and the other body member forms the fuel chamber.

References Cited by the Examiner UNITED STATES PATENTS 885,835 4/08 Brush 103-44 1,711,803 5/29 Munday 103-150 2,058,936 10/36 Zimmer 103-150 2,473,986 6/49 Booth 103-150 2,984,188 5/61 Tuckey et al. 103-44 3,094,074 6/63 Tuckey 103-44 FOREIGN PATENTS 561,591 10/32 Germany.

LAURENCE V. EFNER, Primary Examiner. ROBERT M. WALKER, Examiner. 

1. A PULSE PUMP FOR A FUEL SYSTEM, SAID PUMP COMPRISING A CUP-SHAPED BODY MEMBER, A CYLINDRICAL BODY MEMBER HAVING A SURFACE RECESSED WITHIN ONE END THEREOF, MEANS COAXIALLY MOUNTING SAID BODY MEMBERS TOGETHER WITH THE RIM OF SAID CUP-SHAPED MEMBER TELESCOPICALLY JOINED TO SAID ONE END OF SAID CYLINDRICAL BODY MEMBER, A CIRCULAR DIAPHRAGM POSITIONED ACROSS AND SEALED AT ITS PERIPHERY BETWEEN SAID RIMM OF SAID CUP-SHAPED MEMBER ANDS SAID ONE END OF SAID CYLINDRICAL BODY MEMBER TO FORM AN AIR CHAMBER WITH THE CUP-SHAPED MEMBER AND A FUEL CHAMBER WITH SAID RECESSED SURFACE, SAID CYLINDRICAL BODY MEMBER HAVING AND INLET PASSAGE AND AN OUTLET PASSAGE EXTENDING FROM SAID FUEL CHAMBER, AND CHECK VALVES WITHIN SAID INLET AND OUTLET PASSAGES, SAID CUP-SHAPED MEMBER HAVING A FIRST NIPPLE FOR CONNECTION TO A SOURCE OF AIR PULSATIONS EXTENDING OUTWARDLY THEREFROM AND AWAY FROM THE COMMON AXIS OF SAID MEMBERS, SAID FIRST NIPPLE HAVING A PASSAGE THERETHROUGH OPENING INTO SAID AIR CHAMBER, SAID CYLINDRICAL MEMBER HAVING A SECOND NIPPLE EXTENDING OUTWEARDLY THEREFROM AND AWAY FROM SAID COMMON AXIS, SAID SECOND NIPPLE INCLUDING A PORTION OF SAID FUEL INLET PASSAGE, SAID MOUNTING MEANS COMPRISING AN INTERFITTING LIP AND GROOVE ARRANGEMENT ON SAID CUP-SHAPED BODY MEMBER AND SAID CYLINDRICAL BODY MEMBER TO PERMIT SAID BODY MEMBERS TO BE SNAPPED TOGETHER, SAID LIP AND GROOVE ARRANGEMENT BEING THE SOLE MEANS HOLDING SAID BODY MEMBERS TOGETHER AND SAID DIAPHRAGM IN SEALED RELATION BETWEEN THE BODY MEMBERS AND PROVIDING ANGULAR DISPLACEMENT OF ONE OF SAID MEMBERS RELATIVE TO SAID OTHER MEMBER WHEREBY ONE OF SAID NIPPLES MAY BE INDEXED RELATIVE TO THE OTHER, SAID CYLINDRICAL BODY MEMBER HAVING A CYLINDRICAL RECESS WITHIN THE OTHER END THEREOF TO MOUNT SAID PUMP ON A SUPPORT FOR ROTATION RELATIVE TO THE SUPPORT ABOUT AN AXIS PARALLEL TO THE COMMON AXIS OF THE BODY MEMBERS, THE AXIS OF SAID CYLINDRICAL RECESS BEING SUBSTANTIALLY NORMAL TO SAID NIPPLES TO PROVIDE ANGULAR DISPLACEMENT OF SAID NIPPLES RELATIVE TO SAID SUPPORT. 